Glow-in-dark kitten lend a paw to AIDs fight

Cats that can glow in the dark from a new genetic engineering technique are helping scientists study molecules that could stop AIDS.

So far, the researchers have created three genetically engineered kittens that can glow green and pass this gene onto their offspring. They explained that cats are much better models for AIDS viruses than are mice and other animals.
In addition to opening a window into the virus in humans, the cat research may end up helping the felines themselves, the researchers said.

The world is currently facing two devastating AIDS pandemics— one in humans, the other in domestic cats. The viruses responsible, human immunodeficiency virus (HIV) and feline immunodeficiency virus (FIV), are highly similar.

Researchers have long wanted to genetically experiment with cats to better understand how to combat AIDS. To create genetically modified animals, scientists insert genes into their genomes, often using benign viruses as the delivery vehicles.

Investigators commonly target the earliest possible stages in an animal's development so the gene gets installed into all of its cells — any later, and the gene can end up in some tissues but not others.

At first scientists created genetically engineered cats using cloning, and then implanting the modified nucleus of that cell into an egg cell that had its nucleus removed; the resulting cell then develops into an embryo much like a fertilized egg would. In this manner, researchers generated felines that were either fluorescent red or green, a glow-in-the-dark cat being visible proof of the genetic engineering succeeding.

 However, this kind of cloning is very difficult to perform, as it essentially involves delicate surgery on cells, Now scientists have developed a new way to create genetically engineered domestic cats where they modify egg cells directly with viruses.

"We want to see if we can protect the domestic cat against its AIDS virus, if we can protect any species, eventually including ours, against its own AIDS virus," Scientist Poeschla said.

Scientists created transgenic cats that generated or expressed antiviral proteins taken from rhesus monkeys. Such molecules can block retroviruses such as HIV and FIV.Preliminary results suggested cells from these cats grown in the lab resisted replication of the feline AIDS virus FIV, keeping it from spreading.

This research has tried 22 times and created 5 kittens, but only 3 survived. The researchers stress their work could also help cats themselves, not just humans.